Door lock



O t. 8, 1940. F. A. NILSSON DOOR LOCK 5 Shets-Sheet 1 Filed May 16, 1938Oct. 8, 1940. F. A. NILSSON DOOR LOCK Filed May 16, 1938 5 Sheets-Sheet2 Oct. 8, 1940. F. A. NILSSON DOOR LOCK s Sheets- Sheet :5

Filed May 16, 1938 6*- QM ZWWq Oct. 8, 1940. sso 2,217,131

DOOR LOCK Filed May 16. 1938 5 Sheets-Sheet 4 F. A. NILSSON 2,217,131

DOOR LOCK Filed May 16, 1938 5 Sheets-Sheet 5 T gl 5.

Patented Oct. 8, 1940 DOOR. LOCK Fritz Albert Nilsson, J onkoping,Sweden Application May 16, 1938, Serial No. 208,285 In Sweden November5, 1935 4 Claims.

This invention relates to door locks of the type having a latch-boltwhich is operated by means of handles, when the door is to be opened,and moved into locked position by a spring which is not under tension oris under only a slight tension when the door is open, but isautomatically put under a sufflcient tension to actuate the boltimmediately before the door in its closing movement reaches its fullyclosed position.

An object of the invention is to provide a door lock of the said typewhich does not present any projecting parts in the open position of thedoor and positively prevents operation of the handles as long as thedoor is open. Another object is to secure a practically noiseless,positive closing of the door.

The invention is characterized, chiefly by the fact that the operationof the said spring to put same under tension at' the end of the closingmovement of the door is effected by a slide movable at right angles tothe face of the door which controls, by means of a rocking lever, alever supporting the spring which is mounted to swing in a planeparallel to the face of the door.

In the accompanying drawings, several embodiments of the invention areillustrated.

Fig. 1 is a side elevation, partly in section, of the lock in lockedposition.

Fig. 2 is a horizontal section of the lock on the line A--A of Fig. 1.

Fig. 3 is a horizontal section of the lock on the line B-B of Fig. 1.

Fig. 4 is a vertical section on the line CC of Fig. 1.

Fig. 5 is a side elevation of the look as mounted in the door.

Fig. 6 is a partly sectional side elevation of the lock, with thehandles shown in depressed position to open the door.

Fig. '7 is a partly sectional side elevation of the lock showing theposition of the parts of the lock after the door has been removed fromthe doorpost and the handles have been released.

Fig. 8 is a partly sectional side elevation of a somewhat modifiedconstruction with the parts shown in locked position.

Fig. 9 is a partly sectional side elevation of still another modifiedembodiment of the lock.

Fig. 10 is a sectional view on the line D-D of Fig. 9.

Fig. 11 is a partly sectional side view showing the same parts as Fig. 9with the latch-bolt retracted into the housing of the lock.

Fig. 12 is a partly sectional side elevation of still another embodimentof the lock.

With reference to Figs. 1 -7 of the drawings, the numeral 1 indicatesthe frame of the door, in which the lock is mounted. 2 is the stationarydoor-post and 3 is the keeper plate having an opening to receive thelatch-bolt of the lock. 4 is the housing of the lock mounted in a recessof the door frame, and 5 and 6 are the associated face plates which aresecured by screws 1 to the fore edge of the door. The face plate 6 isthinner than the face plate 5 and is situated outside the same, coveringit completely. The face plates are connected together by a screw orscrews 1 The numeral 8 designates the latch-bolt which is movable in andout through an aperture formed in the face plates 5, 6. The bolt isguided by said aperture and also by a square pin 9 on which the boltrests. Cooperating with the bolt is a rollback l mounted on the squarespindle 12 of the two handles H. Inserted between the rollback In andthe rear wall of the housing 4 is a blade spring 13 adapted to restorethe handles to their uppermost, or normal, position as soon as they arereleased. In this connection the pin 9 acts to limit the movement of therollback. In the housing, below the latch-bolt, a bell crank lever I4 ismounted to rock about a knife edge l secured to the side walls of thehousing. One arm of said bell crank lever which is comparatively thincarries intermediately between its ends a square pin l6 around which aspiral spring I1 is coiled. The upper end of this spring bears against ashoulder of the latch-bolt 8 for urging the same outwards. Said upperend of the spring ll projects beyond the free end of the respective armof the bell crank lever I4 and bears against a lateral projection l8thereof. The spring I! presses against this projection with a slightinitial pressure in certain positions of the bell crank lever. With thespring I! thus bearing against the projection IS, the spring and thebell crank lever form a unitary assembly.

Mounted to reciprocate in a transversely extending slot formed in theinner face plate 5 is a slide l9 guided between the two face plates 5and 6. This slide is formed with an angularly bent extreme end 20 whichin the closing of the door may be operated by an abutment 2| prothereofis flush with the front face of the door,

so that there are no projecting parts at said edge. The main portion ofthe slide I9 situated between the face plates 5, 8 is widerthan the bentend 20. Due to this fact the outward movement of the slide is limited bythe angularly bent projections of face plate 8, Fig. 5. Secured to theface plate 8 is a pivot 22 carrying a rocking lever 28. The end of thisrocking lever situated inside the housing 4 of the lock is adapted toactuate the lower arm 24 of the bell crank lever I4 in order to movesame downwardly. Immediately above the latch-bolt 8 is a weak coilspring 28 which permanently tends to retract the bolt. This coil springhas for its only purpose to prevent the bolt when in its innermostposition from being thrown out, as for instance by the centrifugalforce, when the door is moved quickly. The inner end of the latch-bolt 8is formed with a head 28 against which the fork-shaped upper end of therollback l embracing the latch-bolt bears when the door is opened. Whenthe latch-bolt is in its outermost position, the head 28 cannot touchthe rollback but bears against a soft stop 21 of leather or the like.This stop is held in position by an inwardly bent flap 28 cut out in theside wall of the housing.

The operation is as follows:

Let it be assumed that the door is in'closed position and to be opened.In the closed position of the door all parts of the lock are in thepositions shown in Figs. 1-4. The latchbolt is held in its outermostposition, in engagement with the aperture of the keeper plate 3, underthe action of spring I! which is maintained in this position, under aslight tension,

by the action of the bell crank lever i4, under the control of therocking lever 23 pressing on arm 24 of said bell crank lever. Therocking lever 23 in its turn is maintained in its position by the actionof the abutment 2| and the bent end 20 of slide IS. The handles Ii areheld in their uppermost, horizontal position by the action of spring l3.In order to open the door the handles ii are depressed. This will causethe rollback III to operate the latch-bolt, moving same until it ischecked by the upper end of the spring l1 hitting the pin 9. When thelatch-bolt commences to move inwards, the lever arm 24 tends to moveupwards but will be prevented from doing so by the rocking lever 23,which is held by the end 20 of slide i9. As a result, the spring I! isput under tension and is moved away from the projection l8 into theposition shown in Fig. 6. As soon as the latch-bolt has passed beyondthe edge of the keeper plate 3, the door can be opened. When the door,during the opening movement, has been removed from the doorpost 2, thepressure exerted by the projection 2| upon the slide l9 ceases, allowingthe arm 24 to freely move upwards. In this movement the bell crank lever|4 moves to the right, until its projection i8 again comes into contactwith the spring II. This position is shown in Fig. 'l. The elements willnow remain in this position as long as the door is open, even after thehandles have been released, the release of the handles only resulting ina returning of the rollback to its normal position in engagement withstop 9, without actuating the latch-bolt. While the elements are in thisposition, the spring 25 positively prevents the latch-bolt fromprojecting beyond the door edge from one reason or the other. If, forinstance, a pressure is unintentionally exerted upon the slide l9, whenthe door is open, the elements will immediately return to the positionshown in Fig. 7.

To close the door it is only necessary to push or pull same. When thedoor is at a distance of a few millimeters from the abutting edge of thedoor-post, the end 28 of slide l9 hits the abutment 2| and in thecontinued movement or the door the slide I8 is shifted'from the positionshown in Fig. into the position shown in Figs. 3 and 4. This will turnthe lever |4 into the position shown in Fig. 6 and put the spring undertensiommoving the latch-bolt a little outwards, until its end comes tobear against the keeper plate 3. As soon as the end of the latchboltpasses beyond the lateral edge of the keeper plate, that is, just as thedoor hits the abutting edge of the door-post, the spring II will urgethe latch-bolt out into the opening of the keeper, thereby latching thedoor. The spring 25 is so weak as not to be of any eflect against theinfluence of spring I1. I

Fig. 8 illustrates a modified form of the lock. Instead of using aseparate spring, (as 25) for maintaining the latch-bolt 8 in itsinnermost position, I here utilire the rollback controlling spring IIfor this purpose. To this end the bell crank lever is formed with ashort additional arm 38 directed substantially oppositely to the arm 24.On said short arm 38 presses a lower extension 3| of spring II. Thelatch-bolt is thu held in its innermost position by a weak springaction. This weak spring action is overcome when the arm 24 is depressedin the locking operation so that in this case the entire force or springwill be utilized for moving the latchbolt outwards into engagement withthe doorpost. Fig. 8 also shows a retaining device for the door handlesII with the object in view oi preventing a depressing of the handleswhen the door is open. To this end the bell crank lever i4 is formedwith a detent 32 adapted to cooperate with a projection 33 of therollback. In the locked position shown in Fig. 8, the detent 32 is outof the path of the projection 33. When the latch-bolt is retracted andthe door is open the detent 32, however, will engage the projection 33,thereby preventing a depressing of the handles. Said engagement isreleased at the very instant when the door is closed and the lever arm24 is depressed.

As will appear from Fig. 2, the latch-bolt is symmetrical as seen inplan view. This will permit the use of the lock both for right-hand andleft-hand doors, a shifting from one type of doors to another onlyrequiring a turning over of the face-plate 8 so as to move the slide l9and the bell crank lever 23 to the opposite side of the door. Thischange will move the arm 23 to the upper pin 22 shown in Fig. 4.

In the embodiment shown in Figs. 9-11 the latch-bolt 8, the rollback illand the rollback actuating spring l3 are arranged substantially in thesame way as in the embodiment first described. The latch-bolt is formedwith a downwardly opening recess 33 engaged by one arm 40 of' abell-crank lever 40, 4|, mounted on a knifeedge 42 the other arm 4| ofwhich cooperates with one end of a U-shaped blade spring 43 which mayswing up and down while guided by a strap 44. The upper arm of saidspring carries an arm 45 engaged by the lower arm of the spring forlimiting the movement of the spring arms from each other. The free endof the lower arm of spring 43 rests upon an upwardly directed end of anangularly shaped element 46 mounted in a projecting part 41 of thehousing 4, the downwardly directed point of which bears against atransversely movable slide 48 adapted to codoor-post.

operate with a stationary stop attachdido the end of the angularelementJB is hook-shaped and suspended on a downwardly and laterallybent flap 41 out out from the top wall of the housing part 41, as shownin Fig. 10. The arm 40 of the bell crank lever 40, 4| engaging thelatch-bolt 8 has riveted to it a blade spring 49 bearing against theside of the recess 39 remote from the arm 49 at a point which issituated on a lower level than the contact point between said arm 40 andthe opposite side of the recess. The lower edge of the side of therecess 39 engaged by the arm 40 is rounded, as indicated inFlg. 9, toallow the movement of the latch-bolt without interrupting the contactbetween the arm 40 and the respective side of the recess 39.

The operation of this embodiment is as follows: In the locked positionof the door the elements of the lock are in the positions shown in Figs.9 and 10. When the door is to be opened, the handles are depressedcausing the rollback to retract the latch-bolt 8 into the housing 4against the action of spring l3. In this movement the bell crank lever40, 4| turns about its knife-edge from the position shown in Fig. 9 tothe position shown in Fig. 11. In the said first-mentioned position thespring. 49 is pressed against the arm 40 and according as the latch-bolt8 moves into the housing, the spring 49 is, allowed to retire from thearm 40 due to its spring force. In the inward movement of the latch-boltthe spring 49 will therefore be released to a certain extent. In theabove said turning of the lever 40, 4| the lever arm 4| depresses theupper arm of spring 43, thereby putting the spring under tension. Thisis due to the fact that the lower arm of spring 43 is still inengagement with the angular member 46 and cannot move downwards. As soonas the opening of the door commences, the slide 48, however, is allowedto move outwards and as soon as the slide is out of engagement with thestop of the door-post, it has been moved to its extreme outer positionby the action of spring 43, inasmuch as the lower arm thereof in itstendency to retire from the upper arm of the spring, until it againcomes into contact with the arm 45, turns the angular member 46downwards. As soon as the handles are released, the spring l3 restoresthe rollback to its normal position in contact with the stop 9, therebyrestoring the handles to their uppermost position. This operation,however, has no influence on the latch-bolt, which is maintained in itsinnermost position under the action of a certain spring pressure. Thisis due to the fact that an outward motion of the latch-bolt wouldrequire forcing the spring 49 towards the arm 40 and, consequently, saidspring will ofler a certain resistance to the outward motion of thelatch-bolt which is sufliciently high to prevent the latch-bolt fromsliding outwards due to shaking or rapid swinging of the door.

The locking of the door is effected without depressing the handles,merely by shutting the door. As soon as the slide 49 hits the stationarystop, not shown, it will be urged into the housing 41, causing theangular member 46 to swing upwards with a consequent upward movement ofthe lower arm of spring 43, thereby putting this spring under tension.The spring 43, therefore, tends to turn the bell crank lever 40, 4| intothe position shown in Fig. 9 but is prevented from doing so until afterthe door has been closedfar enough to allow the latch-bolt to enter theaperture of the keeper plate of the door-post. Simi- The other likewiseupwardly directed larly as in the embodiment already described, theputting under tension of the spring controlling the forcing out of thelatch-bolt is only effected just immediately before the forcing out isto take place.

Fig. 12 shows an embodiment which agrees substantially with that shownin Fig. 8 from which it differentiates essentially by the fact that thespring l3 does not only actuate the rollback l0 and the lever l4 toretain the latch-bolt in retracted position but is also formed as a stopfor limiting the outward motion of the latch-bolt. To this end the upperportion 59 of spring I3 is formed with a downwardly bent portion adaptedto be engaged by an elastic block 9| mounted in the rear head 26 of thelatch-bolt.

When the lock is used in connection with new buildings it may happenthat the door or the door-case shrinks so that in the locked position ofthe door there is an undue wide clearance between the keeper plate ofthe door-post and the face plate of the door. This may give rise to asnap when the latch-bolt comes into contact with the keeper plate whenreleased as a result of the slide striking the stationary stop of thedoor-post. In order to avoid this drawback I may provide an adjustablestop to limit the inward movement of the latch-bolt, when the handlesare depressed for opening the door. Such an adjustable stop is shown inFig. 8 in the form of a nut 52 on a screw 53 rotatably mounted in theface plate which is accessible at the front edge of the door. Said stop52 is adapted to be engaged by an inclined surface 54 of the latchbolt8, so that it will be displaced inwards or outwards upon rotation of thescrew 53. When due to shrinking, the clearance between the keeper plateand the face plate in the locked position of the door is too wide, thestop nut 52 may be adjusted by turning the screw 53 so that thelatch-bolt can only be retracted as much as is necessary to allow theopening of the door.

What I claim is:

1. A door lock comprising, in combination, a housing to be mounted in adoor, a latch-bolt, a rollback for actuating said bol-t into unlockedposition,'a spiral spring in constant engagement with said bolt toactuate same into locked position, a lever carrying said spiral spring,said lever being connected with said spring so as to allow the same tobe put under tension without operating the lever upon movement of thebolt into unlocked position, a rocking lever to actuate said springcarrying lever, and a slide movable transversely of the plane of thedoor to control said rocking lever, said slide being released upon theopening of the door so as to allow the spring carrying lever to moveunder the action of the spring into a position to relieve the spring inorder toallow the bolt to remain in its innermost position in the openposition of the door.

2. A door lock comprising, in combination, a housing to be mounted in adoor, a latch-bolt, a shaft extending transversely of the plane of thedoor, a rollback on said shaft to move the bolt into unlocked position,handle means to effect operation of the rollback to unlocked position, aspring to actuate the bolt into locked position, a lever carrying saidspring, means for controlling said lever to cause it to put the springunder tension at the end of the closing movement of the door, therollback and said spring carrying lever being formed with projections toengage each other for preventing operation of the rollback and itshandle means in the open position oi. the door.

3. A door lock comprising, in combination, a housing to be mounted in adoor, a latch-bolt, a rollback to actuate said bolt into unlockedposition, a spring free of tension in the open position of the door toactuate said bolt into locked position, a lever carrying said spring, arocking lever to actuate said spring carrying lever, a transverselymovable slide to actuate said rocking lever to cause it to put thespring under tension due to the slide striking a stationary stop at theend of the closing movement of the door, and adjustable means to limitthe inward motion of the bolt when actuated by the rollback.

tion of the door, means for operating said lever to bring its projectionout of engagement with said spring at the end of the closing movement ofthe door, and a spring to maintain the iatch bolt retracted in thehousing of the lock in the open position of the door.

FRITZ ALBERT NILSSON.

